package lab02.test28;

        import java.util.InputMismatchException;
        import java.util.Scanner;

public class Test28 {
    public static void main(String[] args) {
        double radius = 0;
        Scanner scanner = new Scanner(System.in);

        System.out.println("please input radius");

        try {
            radius=scanner.nextDouble();
        }catch(InputMismatchException e){
            System.out.println("输入的数据不是double型数据");
        }

        double area = 0;
        System.out.println( area+"=" +radius + "*" + radius + "*" + 3.14 );
    }
}